bug 91171 adding support for webdings font.

/r=ftnag, /sr=sspitzer

gfx/src/windows/fontEncoding.properties

@@ -80,6 +80,7 @@ encoding.math5monobold.ttf  = x-mathematica5
 # MathType Extra
 encoding.mtextra.ttf = x-mtextra
 
-# Hack for compatibility with Nav4.x (bug 77265)
+# Hack for compatibility with Nav4.x (bug 77265, 91171)
 # Treat these Symbol fonts as if they have the given encoding
 encoding.wingdings.ttf = windows-1252
+encoding.webdings.ttf = windows-1252